During medical procedures as well as pre and post operation conditions, monitoring of fluid pressure within the patient is necessary in conjunction with the assessment of the patient care and treatment. The fluid pressure monitoring is most commonly arterial blood pressure, but knowledge concerning intracranial fluid pressure, venous pressure, and intraheart pressure also can provide important insight into a patient's current condition. One of the most effective devices for these types of measurements is a pressure transducer directly communicating with the particular bodily fluid of interest. Typically, the patient is catheterized and a tube, usually containing saline fluid pressure, provides a fluid communication path between the bodily fluid and the pressure transducer. Then, the electrical impulses generated by the pressure transducer, which are a function of the bodily fluid pressure, are displayed by a monitor or other display device to monitor specific body functions.
The transducer housing is usually mounted in close proximity to the patient on an I.V. pole with the I.V. bag providing the saline solution. If the user desires only information regarding the dynamics of the bodily fluid pressure, then the pressure transducer can be mounted virtually anywhere vertically on the I.V. pole. If the user, however, desires to monitor the absolute pressure of the bodily fluid, then the pressure transducer must be mounted in a fixed relationship to the patient. For example, if arterial pressure is to be monitored, then the pressure transducer must be mounted approximately at the level of the heart.
A continuing need exists to provide accurate reproducible methods for monitoring hemodynamic pressure. Variations in the position of the sensor system relative to the patient continue to result in improper assessment of the patient's condition which may adversely affect decisions regarding the course of treatment including selection of medications administered to adjust fluid pressure.